Replace 'lvconvert' from rootwrap

Use oslo.privsep to run the lvconvert command.

Change-Id: I6c2dce7beb1c3f8bb777066f62ced134f763e640
Signed-off-by: Charles Short <chucks@redhat.com>

cinder/brick/local_dev/lvm.py

@@ -747,10 +747,8 @@ class LVM(executor.Executor):
         :param snapshot_name: Name of snapshot to revert
         """
 
-        cmd = ['lvconvert', '--merge', '%s/%s' % (self.vg_name, snapshot_name)]
         try:
-            self._execute(*cmd, root_helper=self._root_helper,
-                          run_as_root=True)
+            cinder.privsep.lvm.lvconvert(self.vg_name, snapshot_name)
         except putils.ProcessExecutionError as err:
             LOG.exception('Error Revert Volume')
             LOG.error('Cmd     :%s', err.cmd)

cinder/privsep/lvm.py

@@ -36,3 +36,9 @@ def lvrename(vg_name, lv_name, new_name):
 def create_vg(vg_name, pv_list):
     cmd = ['vgcreate', vg_name, ','.join(pv_list)]
     processutils.execute(*cmd)
+
+
+@cinder.privsep.sys_admin_pctxt.entrypoint
+def lvconvert(vg_name, snapshot_name):
+    processutils.execute(
+        'lvconvert', '--merge', '%s/%s' % (vg_name, snapshot_name))

etc/cinder/rootwrap.d/volume.filters

@@ -68,9 +68,6 @@ lvextend_lvmconf_fdwarn: EnvFilter, env, root, LVM_SYSTEM_DIR=, LC_ALL=C, LVM_SU
 # cinder/brick/local_dev/lvm.py: 'lvchange -a y -K <lv>'
 lvchange: CommandFilter, lvchange, root
 
-# cinder/brick/local_dev/lvm.py: 'lvconvert', '--merge', snapshot_name
-lvconvert: CommandFilter, lvconvert, root
-
 # cinder/volume/driver.py: 'iscsiadm', '-m', 'discovery', '-t',...
 # cinder/volume/driver.py: 'iscsiadm', '-m', 'node', '-T', ...
 iscsiadm: CommandFilter, iscsiadm, root